Investigating Synergistic Combinations of MRT68921 and Afatinib as a Therapeutic Strategy in Epithelial Ovarian Cancer
Abstract
Epithelial ovarian cancer is the most lethal gynaecological cancer in the developed world. Spheroids, multicellular aggregates that disseminate into the peritoneal cavity are mediators of disease progression. Autophagy supports spheroid survival and is linked to chemoresistance. This study investigates inhibition of unc51-like-kinase 1 (ULK1), an autophagy regulator, using MRT68921 and its combination with tyrosine kinase inhibitor afatinib. Immunoblotting confirmed MRT68921 inhibits ULK1 activity at low micromolar concentrations, reducing phosphorylation of Beclin1 Ser30 within 30 minutes, and for 96 hours. Spheroids stably expressing mCherry-eGFP-LC3B demonstrated that MRT68921 inhibits autophagic flux, while afatinib increases it. Increased LC3II/I detected via immunoblotting is consistent with afatinib-induced autophagy. Synergy Finder identified synergistic combinations and spheroid viability assays demonstrated that MRT68921 drives reduced viability in spheroids. Ascites-derived organoids were sensitive to MRT68921 and afatinib, with many treatment conditions reducing viability by 50% or more. These findings suggest a novel therapeutic strategy that warrants further evaluation.